Högdalenverket is one of energy company Fortum's power plants. Here household waste is incinerated to produce electricity using two steam turbines, with the remaining energy being channelled into the district-heating newtwork. The process is hard on the plant, yet high standards of uptime and reliability are essential. In the event of an unscheduled stoppage, the plant has to switch to alternative fuels such as oil, which is very expensive. To minimise the risk of unpleasant surprises, Fortum needs reliable inspection and testing methods and so has commissioned ÅF to inspect and test the plant's boilers and pressure vessels. The thickness of the boiler tubes is tested continously. When repairs and modifications are made, ÅF performs X-ray, crack indication and ultrasound tests. During the scheduled stoppages made to date, ÅF has identified a number of problems, enabling them to be dealt with before they cause costly unscheduled stoppages.